Rusting

Question 1

Why is corrosion a problem?

Answer 1

Corrosion is a dangerous and extremely costly problem. Because of it, buildings and bridges can collapse, oil pipelines break, chemical plants leak, and bathrooms flood.

Question 2

What is corrosion?

Answer 2

The breaking down of any metal by environmental substances.

Question 3

What substances in the environment can cause corrosion?

Answer 3

Water.
Oxygen.
Acid rain.
Salt.

Question 4

What does rusting need to occur?

Answer 4

Iron needs to be in contact with both oxygen and water.

Question 5

What is the word and balanced symbol equation for rusting?

Answer 5

Iron + Oxygen + Water → Hydrated Iron (III) Oxide.
4Fe +3O₂ + 6H₂O → 4Fe(OH)₃

Question 6

What type of reaction is rusting and why?
Write a half equation.

Answer 6

An oxidation reaction.
Iron gains oxygen to become hydrated iron oxide.
Iron loses electrons to become Fe³⁺.
Fe - 3e⁻ → Fe³⁺

Question 7

What’s the first techniques to prevent rusting?

Answer 7

Oiling (bicycle chains)
Greasing (nuts and bolts)
Painting (car body panels)
These stop oxygen or water reaching the surface of the metal.

Question 8

What’s the second technique to prevent rusting?

Answer 8

Using tin plating protects food reacting in steel cans.
You can put a thin layer of tin between the steel and the food.

Question 9

What’s the third technique to prevent rusting?

Answer 9

Sacrificial Protection:
Attach a more reactive metal to iron, so they react instead.
Magnesium and Zinc can be used.

Question 10

What’s the only metal that can rust?

Answer 10

Iron